Heat exchangers comprising various types of sensors for measuring various operating parameters such as the temperature and pressure of the fluid passing through a heat exchanger are known. Sensors for detecting fluid leakage in a heat exchanger are also known.
British patent specification GB 2062833-A describes a heat exchanger for, inter alia, a health-damaging fluid. The heat exchanger is made up of heat exchanger plates which have portholes, are welded together in pairs and are installed with gaskets between each pair of welded plates. The region round the ports comprises a first gasket which is situated close to the port orifice and thereby has fluid contact round it, and a second gasket which is situated outside the first gasket so that a space is formed between the gaskets. In the event of leakage through the first gasket, fluid enters the space between the gaskets and is thereby prevented from mixing with other fluid in the heat exchanger. A sensor is installed in such a way that it extends through the second gasket and into the space between the gaskets. The purpose of the sensor is to monitor and indicate fluid entering the space between the gaskets, which will mean that the first gasket nearest to the port has failed and needs changing. The disadvantage of the invention according to GB 2062833-A is that only when the gasket has failed and leakage in the heat exchanger has already occurred does the sensor provides an indication.
European patent specification EP 0520380-A1 describes a gasket for a vehicle engine, which gasket comprises sensors for pressure monitoring. The sensor is situated between two gasket halves together with seal means for preventing direct contact with fluid. The disadvantage of the invention according to EP 0520380-A1 is the complicated gasket structure which means that the gasket is expensive to manufacture and involves a number of manufacturing steps to finished product. A further disadvantage of gaskets made up of a number of parts is that the parts may delaminate from one another, which may result in the gasket starting to leak. A further disadvantage is that the sensors are only intended to measure pressure in the gasket, and the arrangement is not equipped for assessing the risk of leakage due to the gasket having failed. A further disadvantage of the gasket is that its configuration is such that it is impossible to apply it to heat exchanger plates, since it is designed to seal between two relatively large flat surfaces and not for fitting into a gasket recess in a heat exchanger plate.